PASSIVE ANKLE DORSIFLEXION IN THE MANAGEMENT OF KNEE OSTEOARTHRITIS IN OLDER ADULTS – A RANDOMISED CONTROLLED TRIAL

¹Hong Kong Polytechnic University, Hong Kong, Hong Kong

Background: Passive mobilization with submaximal bilateral passive ankle dorsiflexion was examined in a double-blinded randomized controlled clinical trial and a longitudinal study on its effect in knee osteoarthritis. A passive ankle dorsiflexion apparatus (PANDA) was used to standardize the frequency, range of motion, and duration parameters.

Purpose: The purpose of this study was to examine the effectiveness of using bilateral ankle dorsiflexion, applied through a mechanical device, in the management of knee osteoarthritis.

Methods: The study was carried out in three phases.In phase 1, a prototype of the PANDA device was designed and developed.In phase 2, 73 participants were randomly assigned to the experimental or control group. All participants performed active exercises and received six sessions of 10-minute dorsiflexion intervention, either experimental or sham (30° or 5° of passive dorsiflexion respectively from 30° plantar flexion starting position), for two weeks. Pre- and post-experimental assessments for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analog scale (VAS) for pain, and range of motion of the knee were conducted.In phase 3, 35 participants took part in a longitudinal study with 4 weeks (8 sessions) of PANDA treatment, followed by 4 weeks of home exercises. Outcome measures also included Oxford Knee Score (OKS) and Timed Up and Go Test (TUG).

Results: Results were analyzed using two-way repeated measures analysis of variance.In phase 2, the mean score of WOMAC for the experimental and control groups changed from 31.8 to 18.2 and 34.7 to 21.1 (p<0.05), respectively, after the intervention. The VAS also showed significant improvements (p<0.05). Significant improvements were observed in WOMAC in both groups after the intervention.However, differences between the experimental and control groups were not statistically significant.In phase 3, WOMAC changed from25.9 to 18.1 and then to 14.9 (p<0.05); OKS changed from 33.8 to 36.5 and then to 38.4 (p<0.05).VAS changed from 2.9 to 2.0 and then to 1.8 (p<0.05) and TUG changed from 9.9s to 7.9s and then to 7.6s.There was no significant change in ROM.

Conclusions: The use of PANDA for the application of passive ankle dorsiflexion was demonstrated to be safe without evidence of adverse effects. Exercise with either 30° or 5° of passive dorsiflexion applied by PANDA was shown to yield favorable clinical effects.The longitudinal study showed that there were significant improvements in all outcome measures except ROM after PANDA treatment.

Implications: The use of bilateral passive ankle dorsiflexion was a safe and effective management of knee osteoarthritis, especially when coupled with active exercises.The production of a mechanical device performing such mobilization may help in the clinical and self-management of knee osteoarthritis of older adults.

Funding acknowledgements: It is a self-financed project with no funding from third parties.

Keywords:
Knee
Osteoarthritis
Mobilization

Topics:
Musculoskeletal: lower limb
Disability & rehabilitation
Older people

Did this work require ethics approval? Yes

Institution: The Education University of Hong Kong

Committee: Human Research Ethics Committee

Ethics number: 2017-2018-0395